Optical fiber unit and machining method for optical fiber unit

ABSTRACT

A machining method for an optical fiber unit, includes: preparing an optical fiber unit in which a first optical fiber ribbon that intermittently connects a first plurality of optical fibers and a second optical fiber ribbon that intermittently connects a second plurality of optical fibers are layered and arranged, the first optical fiber ribbon and the second optical fiber ribbon are intermittently connected in a length direction by interlayer connection parts; opening up a separation part between the first optical fiber ribbon and the second optical fiber ribbon; and breaking the interlayer connection parts by inserting a finger or a division tool into the opened separation part.

TECHNICAL FIELD

The present invention relates to an optical fiber unit and a machiningmethod for an optical fiber unit.

BACKGROUND

Patent Literatures 1 to 6 describe an optical fiber ribbon(intermittently connected optical fiber ribbon) in which three ormore-core optical fibers arranged side by side are intermittentlyconnected. Patent Literature 7 describes an optical fiber unit in whicha plurality of optical fibers are circularly connected. PatentLiterature 8 describes an optical fiber unit in which a plurality ofoptical fibers are arranged in two lines and many rows and areintermittently connected. Patent Literature 9 describes that a pluralityof intermittently connected optical fiber ribbons are aligned in one rowon a plane and intermittently connected.

PATENT LITERATURE

-   Patent Literature 1: JP 2015-219355A-   Patent Literature 2: JP 2016-184170A-   Patent Literature 3: JP 2017-026754A-   Patent Literature 4: JP 2013-088617A-   Patent Literature 5: JP 2016-001338A-   Patent Literature 6: JP 2010-008923A-   Patent Literature 7: JP 2012-208223A-   Patent Literature 8: JP 2013-109172A-   Patent Literature 9: JP 2014-016528A

The optical fiber unit described in Patent Literatures 7 and 8 arranges,in many stages or circularly, a plurality of optical fibers constitutingone optical fiber ribbon, and a plurality of optical fiber ribbons arenot constituted. The optical fiber unit described in Patent Literatures7 and 8 is configured to arrange a plurality of optical fibersconstituting one optical fiber ribbon in many stages or circularly, andthus it may be difficult to determine a position of a predeterminedoptical fiber (for example, a first optical fiber).

In the optical fiber unit described in Patent Literature 9, a boundarybetween an optical fiber ribbon and an optical fiber ribbon needs to bedetermined by determining a difference in connection pattern. Thus, inthe optical fiber unit described in Patent Literature 9, it may bedifficult to determine a position of a predetermined optical fiber (forexample, a first optical fiber).

SUMMARY

One or more embodiments provide an optical fiber unit that includes aplurality of optical fiber ribbons, and makes it easy to determine aposition of a predetermined optical fiber of each of the optical fiberribbons. One or more embodiments provide a new machining method for suchan optical fiber unit.

In one or more embodiments, an optical fiber unit comprises: a firstoptical fiber ribbon that is an intermittently connected optical fiberribbon intermittently connecting N optical fibers; a second opticalfiber ribbon that is an intermittently connected optical fiber ribbonintermittently connecting N optical fibers; and interlayer connectionparts that intermittently connect the first optical fiber ribbon and thesecond optical fiber ribbon in a length direction while the firstoptical fiber ribbon and the second optical fiber ribbon are layered andarranged, wherein the first optical fiber ribbon and the second opticalfiber ribbon are layered and arranged such that optical fibers having asame fiber number of the first optical fiber ribbon and the secondoptical fiber ribbon are aligned.

Other features of embodiments of the invention are made clear by thefollowing description and the drawings.

With one or more embodiments of the present invention, it is easy todetermine a position of a predetermined optical fiber of each opticalfiber ribbon.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1A is an explanatory diagram of an optical fiber unit 10 accordingto one or more embodiments.

FIG. 1B is a cross-sectional view in a position including an interlayerconnection part 22. FIG. 1C is a cross-sectional view in a position thatdoes not include the interlayer connection part 22.

FIG. 2 is an explanatory diagram of an intermittently connected opticalfiber ribbon 11 in which single-core fibers are intermittentlyconnected.

FIG. 3 is an explanatory diagram of another intermittently connectedoptical fiber ribbon 11.

FIG. 4A is a cross-sectional view of two optical fibers 1 connected byan in-layer connection part 12. FIG. 4B is a cross-sectional view of twooptical fibers 1 connected by the interlayer connection part 22.

FIG. 5A is an explanatory diagram of an optical fiber unit 10 accordingto one or more embodiments when viewed from a width direction. FIG. 5Bis an explanatory diagram of a situation where an interlayer separationpart 23 of a first tape 11A and a second tape 11B is opened up.

FIG. 6 is an explanatory diagram of a manufacturing system 30 formanufacturing the optical fiber unit 10.

FIGS. 7A and 7B are explanatory diagrams of a taping device 44.

FIG. 8A is an explanatory diagram of a unitization device 32. FIG. 8B isan explanatory diagram of another application unit 321.

FIG. 9 is a flowchart of an example of a machining method for theoptical fiber unit 10.

FIGS. 10A and 10B are explanatory diagrams of a situation where theoptical fiber unit 10 is set in a holder 50.

FIGS. 11A to 11C are explanatory diagrams of a situation where sheathsof optical fibers 1 of the optical fiber unit 10 are removed.

FIGS. 12A to 12C are explanatory diagrams of the optical fiber unit 10according to a modification example of one or more embodiments.

FIG. 13 is an explanatory diagram of a situation where the optical fiberunit 10 according to the modification example illustrated in FIG. 12A isset in the holder 50.

FIGS. 14A and 14B are explanatory diagrams of an optical fiber unit 10according to one or more embodiments.

FIGS. 15A and 15B are explanatory diagrams of an optical fiber unit 10according to a modification example.

DETAILED DESCRIPTION

At least the following matters are made clear from the followingdescription and the drawings.

An optical fiber unit will become clear, comprising: a first opticalfiber ribbon that is an intermittently connected optical fiber ribbonintermittently connecting N optical fibers; a second optical fiberribbon that is an intermittently connected optical fiber ribbonintermittently connecting N optical fibers; and interlayer connectionparts that intermittently connect the first optical fiber ribbon and thesecond optical fiber ribbon in a length direction while the firstoptical fiber ribbon and the second optical fiber ribbon are layered andarranged, wherein the first optical fiber ribbon and the second opticalfiber ribbon are layered and arranged such that optical fibers having asame fiber number of the first optical fiber ribbon and the secondoptical fiber ribbon are aligned. With the optical fiber unit, it iseasy to determine a position of a predetermined optical fiber of eachoptical fiber ribbon.

It is preferable that the optical fiber in an end part of the firstoptical fiber ribbon and the optical fiber in an end part of the secondoptical fiber ribbon are connected by the interlayer connection parts.In this way, work for breaking the interlayer connection parts isfacilitated.

It is preferable that the interlayer connection parts that connect firstoptical fibers to each other and the interlayer connection parts thatconnect N-th optical fibers to each other are formed in a same positionin the length direction. In this way, it is easy to maintain a shape ofthe optical fiber unit.

It is preferable that the interlayer connection parts that connect firstoptical fibers to each other and the interlayer connection parts thatconnect N-th optical fibers to each other are formed in differentpositions from each other in the length direction. In this way, it ispossible to maintain a shape of the optical fiber unit by a small numberof the interlayer connection parts.

It is preferable that an interval P2 is longer than an interval P1,where P1 is an interval in which in-layer connection parts that eachintermittently connects the optical fibers of the first optical fiberribbon or the second optical fiber ribbon are aligned in the lengthdirection, and P2 is an interval in which the interlayer connectionparts are aligned in the length direction. In this way, it is easy towiden a separation part (interlayer separation part) between the firstoptical fiber ribbon and the second optical fiber ribbon of the opticalfiber unit.

It is preferable that a length A2 is shorter than a length A1, where A1is a length in the length direction of an in-layer connection part thatintermittently connects the optical fibers of the first optical fiberribbon or the second optical fiber ribbon, and A2 is a length in thelength direction of the interlayer connection part. In this way, it iseasy to break the interlayer connection part while the in-layerconnection part is maintained.

It is preferable that the interlayer connection parts are formed on alayer of a connection agent constituting in-layer connection parts thatintermittently connect the optical fibers of the first optical fiberribbon or the second optical fiber ribbon. It is easy to break theinterlayer connection part while the in-layer connection part remains.

It is preferable that in-layer connection parts that intermittentlyconnect the optical fibers of the first optical fiber ribbon or thesecond optical fiber ribbon are not formed in a section in which theinterlayer connection parts of the optical fibers are formed. In thisway, it is possible to suppress a transmission loss.

The optical fiber unit preferably, further comprises a third opticalfiber ribbon that is an intermittently connected optical fiber ribbonthat intermittently connects N optical fibers, wherein interlayerconnection parts that intermittently connect the first optical fiberribbon and the second optical fiber ribbon in the length direction andinterlayer connection parts that intermittently connect the secondoptical fiber ribbon and the third optical fiber ribbon in the lengthdirection are formed in a same position in the length direction. In thisway, it is easy to form two interlayer connection parts aligned in anup-down direction.

The optical fiber unit preferably, further comprises a third opticalfiber ribbon that is an intermittently connected optical fiber ribbonintermittently connecting N optical fibers, wherein interlayerconnection parts that intermittently connect the first optical fiberribbon and the second optical fiber ribbon in the length direction andinterlayer connection parts that intermittently connect the secondoptical fiber ribbon and the third optical fiber ribbon in the lengthdirection are formed in different positions from each other in thelength direction.

It is possible to perform an arrangement such that a position in thelength direction of a separation part (interlayer separation part)between the first optical fiber ribbon and the second optical fiberribbon is shifted with respect to a position in the length direction ofa separation part (interlayer separation part) between the secondoptical fiber ribbon and the third optical fiber ribbon, and thus workfor taking out a desired optical fiber ribbon from the optical fiberunit is facilitated.

A machining method for an optical fiber unit will become clear, themachining method comprising: preparing an optical fiber unit in which afirst optical fiber ribbon that is an intermittently connected opticalfiber ribbon and a second optical fiber ribbon that is an intermittentlyconnected optical fiber ribbon which are layered and arranged areintermittently connected in a length direction by interlayer connectionparts; opening up a separation part between the first optical fiberribbon and the second optical fiber ribbon by applying force in thelength direction to the optical fiber unit to reduce an interval betweenthe interlayer connection parts; and breaking the interlayer connectionparts by inserting a finger or a division tool into the openedseparation part. With such a machining method, work for breaking theinterlayer connection part of the optical fiber unit is facilitated.

A machining method for an optical fiber unit will become clear, themachining method comprising: preparing an optical fiber unit in which afirst optical fiber ribbon that is an intermittently connected opticalfiber ribbon and a second optical fiber ribbon that is an intermittentlyconnected optical fiber ribbon which are layered and arranged areintermittently connected in a length direction by interlayer connectionparts; separating a plurality of optical fibers of the first opticalfiber ribbon and a plurality of optical fibers of the second opticalfiber ribbon into single fibers in an end part of the optical fiberunit; and arranging the plurality of optical fibers in one row bysetting the optical fiber unit in a holder including a base part and alid part, and sandwiching the plurality of layered and arranged opticalfibers of the optical fiber unit between the base part and the lid part.With such a machining method, it is possible to machine the opticalfibers of the optical fiber unit by using a normal tool.

The machining method for an optical fiber unit preferably, furthercomprising: setting, in a sheath removing device, the holder in whichthe plurality of optical fibers of the optical fiber unit are arrangedin one row; and removing sheaths of the plurality of optical fibers ofthe first optical fiber ribbon and sheaths of the plurality of opticalfibers of the second optical fiber ribbon together by a pair of bladesof the sheath removing device. In this way, it is possible to line uppeeling edges of the sheaths.

The machining method for an optical fiber unit preferably, furthercomprising: setting, in a cutting device, the holder in which theplurality of optical fibers of the optical fiber unit are arranged inone row; and cutting the plurality of optical fibers of the firstoptical fiber ribbon and the plurality of optical fibers of the secondoptical fiber ribbon together by moving a cutting blade of the cuttingdevice in a direction in which the plurality of optical fibers arealigned. In this way, it is possible to line up endfaces of the opticalfibers.

Optical Fiber Unit 10:

FIG. 1A is an explanatory diagram of an optical fiber unit 10 accordingto one or more embodiments. FIG. 1B is a cross-sectional view in aposition including an interlayer connection part 22. FIG. 1C is across-sectional view in a position that does not include the interlayerconnection part 22. FIGS. 1B and 1C illustrate an identification number(fiber number) of an optical fiber 1 inside a circle indicating theoptical fiber 1.

In the following description, a direction parallel to an optical axisdirection of the optical fiber 1 may be referred to as a “lengthdirection”. A direction in which a plurality of (here 12) optical fibers1 constituting each intermittently connected optical fiber ribbon 11 (afirst tape 11A or a second tape 11B) are aligned may be referred to as a“width direction”. A direction in which the two intermittently connectedoptical fiber ribbons 11 (the first tape 11A and the second tape 11B)are aligned may be referred to as an “up-down direction”.

The optical fiber unit 10 according to one or more embodiments includestwo intermittently connected optical fiber ribbons 11. The twointermittently connected optical fiber ribbons 11 are aligned in theup-down direction. In other words, the two intermittently connectedoptical fiber ribbons 11 are layered and arranged with tape surfacesfacing each other. In the following description, one of theintermittently connected optical fiber ribbons 11 may be referred to asthe “first tape 11A”, and the other intermittently connected opticalfiber ribbon 11 adjacent to the first tape 11A may be referred to as the“second tape 11B”. Note that, when each of the plurality ofintermittently connected optical fiber ribbons 11 constituting theoptical fiber unit 10 is provided with a tape number, a first tape isthe first tape 11A, and a second tape is the second tape 11B.

Each of the intermittently connected optical fiber ribbons 11 (the firsttape 11A or the second tape 11B) includes a plurality of (N) opticalfibers 1. In one or more embodiments, each of the intermittentlyconnected optical fiber ribbons 11 (the first tape 11A or the secondtape 11B) includes 12 optical fibers 1. In other words, theintermittently connected optical fiber ribbon 11 according to one ormore embodiments is an N-core optical fiber ribbon. The plurality ofoptical fibers 1 constituting the intermittently connected optical fiberribbon 11 are each provided with a fiber number. In a case of the N-coreoptical fiber ribbon, the N optical fibers 1 from a first fiber 1A to anN-th fiber 1N are aligned in order in the width direction. Note that aconfiguration of the intermittently connected optical fiber ribbon 11will be described later.

In one or more embodiments, the two intermittently connected opticalfiber ribbons 11 are aligned in the up-down direction such that theoptical fibers 1 having the same fiber number are aligned in the up-downdirection. For example, the first fiber 1A of the first tape 11A and thefirst fiber 1A of the second tape 11B are aligned in the up-downdirection. In this way, the optical fibers 1 having the same fibernumber are aligned in the up-down direction, and thus it is easy todetermine a position of a predetermined optical fiber 1 (for example,the first fiber 1A), and handling of the optical fiber 1 is facilitated.

The first tape 11A and the second tape 11B are intermittently connectedby an interlayer connection part 22. The interlayer connection part 22is a section that connects the two intermittently connected opticalfiber ribbons 11 adjacent to each other in the up-down direction. Theinterlayer connection part 22 may be referred to as a “tape connectionpart” or a “second connection part”. The plurality of interlayerconnection parts 22 are arranged intermittently in the length direction.In other words, the plurality of interlayer connection parts 22 arearranged at an interval. An interlayer separation part 23 is formedbetween the interlayer connection part 22 and the interlayer connectionpart 22 intermittently arranged in the length direction. Thus, theinterlayer connection part 22 and the interlayer separation part 23 arealternately arranged in the length direction. In the interlayerseparation part 23, the two intermittently connected optical fiberribbons 11 adjacent to each other are not connected. In other words, inthe interlayer separation part 23, the two intermittently connectedoptical fiber ribbons 11 adjacent to each other are not restrained.

The interlayer connection part 22 is formed by curing an adhesive. Forexample, the interlayer connection part 22 is formed by, afterapplication of ultraviolet curing resin to serve as an adhesive, curingthe ultraviolet curing resin by irradiation with ultraviolet rays. Notethat the interlayer connection part 22 may be formed of thermoplasticresin.

As described above, in one or more embodiments, while the first tape 11Aand the second tape 11B are layered and arranged such that the opticalfibers 1 having the same fiber number of the first tape 11A and thesecond tape 11B are aligned, the first tape 11A and the second tape 11Bare intermittently connected by the interlayer connection part 22 in thelength direction. In this way, it is easy to determine a position of apredetermined optical fiber of each optical fiber ribbon 11. Thus,handling of the multitude of optical fibers 1 of the optical fiber unit10 is facilitated.

In one or more embodiments, the interlayer connection part 22 is formedin an end part in the width direction. When end parts in the widthdirection of the plurality of N-core intermittently connected opticalfiber ribbons 11 are connected, the interlayer connection part 22 in oneof the end parts in the width direction connects the first fibers 1A,and the interlayer connection part 22 in the other end part in the widthdirection connects the N-th fibers 1N. In one or more embodiments, sincethe optical fiber unit 10 is formed of the two 12-core intermittentlyconnected optical fiber ribbons 11, the interlayer connection part 22 inone of the end parts connects the first fiber 1A of the first tape 11Aand the first fiber 1A of the second tape 11B, and the interlayerconnection part 22 in the other end part (on an opposite side) alsoconnects a twelfth fiber 1N of the first tape 11A and a twelfth fiber 1Nof the second tape. Note that the interlayer connection part 22 may beformed on the inside in the width direction.

As described above, in one or more embodiments, since the interlayerconnection part 22 is formed only in the end part in the widthdirection, the two optical fiber ribbons 11 adjacent to each other inthe up-down direction are restrained only in the end part in the widthdirection and are not restrained in a central part in the widthdirection. In this way, it is easy to roll up the optical fiber unit 10into a bundle, and it is easy to bundle the multitude of optical fibers1 with high density into an optical cable. In one or more embodiments,since the interlayer connection part 22 is formed only in the end partin the width direction, work for breaking the interlayer connection part22 is facilitated when the intermittently connected optical fiber ribbon11 is taken out from the optical fiber unit 10. However, optical fibersother than an end part may be connected to each other by the interlayerconnection part 22.

In one or more embodiments, as illustrated in FIG. 1B, the interlayerconnection part 22 that connects the first fibers 1A to each other andthe interlayer connection part 22 that connects the N-th fibers 1N toeach other are formed in the same position in the length direction. Inthis way, it is easy to maintain a shape of the optical fiber unit 10.However, the interlayer connection part 22 that connects the firstfibers 1A to each other and the interlayer connection part 22 thatconnects the N-th fibers 1N to each other may be formed in differentpositions (for example, in alternate positions) in the length direction.In this way, a shape of the optical fiber unit 10 can be maintained by asmall number of the interlayer connection parts 22.

FIG. 2 is an explanatory diagram of the intermittently connected opticalfiber ribbon 11 in which single-core fibers are intermittentlyconnected.

The intermittently connected optical fiber ribbon 11 is an optical fiberribbon including the plurality of optical fibers 1 arranged side by sideand connected intermittently. Two optical fibers 1 adjacent to eachother are connected by an in-layer connection part 12. The in-layerconnection part 12 is a section that connects the two optical fibers 1adjacent to each other in the width direction. Note that the in-layerconnection part 12 may be referred to as a “fiber connection part” or a“first connection part”. The plurality of in-layer connection parts 12are arranged intermittently and two-dimensionally in the lengthdirection and the width direction. The plurality of in-layer connectionparts 12 are arranged intermittently in the length direction between thetwo optical fibers 1 adjacent to each other. A non-connected part 13(separation part) is formed between the in-layer connection part 12 andthe in-layer connection part 12 intermittently arranged in the lengthdirection. Thus, the in-layer connection part 12 and the non-connectedpart 13 are alternately arranged in the length direction. In thenon-connected part 13, the two optical fibers 1 adjacent to each otherare not restrained. The non-connected part 13 is arranged in the widthdirection of a position in which the in-layer connection part 12 isformed. In this way, the intermittently connected optical fiber ribbon11 can be rolled up into a bundle, and the multitude of optical fibers 1can be bundled with high density into an optical cable.

The in-layer connection part 12 is formed by curing an adhesive. Forexample, the in-layer connection part 12 is formed by, after applicationof ultraviolet curing resin to serve as an adhesive, curing theultraviolet curing resin by irradiation with ultraviolet rays. Note thatthe in-layer connection part 12 may be formed of thermoplastic resin.

FIG. 3 is an explanatory diagram of another intermittently connectedoptical fiber ribbon 11. The optical fiber ribbon 11 includes aplurality of (here six) pairs (fiber pairs 7) of two-line optical fibers1 continuously connected in the length direction, and the fiber pairs 7adjacent to each other are intermittently connected by the in-layerconnection part 12. In the intermittently connected optical fiber ribbon11, the non-connected part 13 is arranged in the width direction of aposition in which the in-layer connection part 12 is formed. In thisway, the optical fiber ribbon 11 can be rolled up into a bundle. Also inthe intermittently connected optical fiber ribbon 11, the plurality ofin-layer connection parts 12 that connect the fiber pairs 7 adjacent toeach other are intermittently arranged in the length direction, and thenon-connected part 13 is formed between the in-layer connection part 12and the in-layer connection part 12. In other words, also in theintermittently connected optical fiber ribbon 11, the in-layerconnection part 12 and the non-connected part 13 are alternatelyarranged in the length direction.

Note that the intermittently connected optical fiber ribbon 11 is notlimited to that illustrated in FIGS. 2 and 3 . For example, thearrangement of the in-layer connection part 12 may be changed, and thenumber of the optical fibers 1 may be changed.

FIG. 4A is a cross-sectional view of two optical fibers 1 connected bythe in-layer connection part 12. Note that FIG. 4A is also across-sectional view taken along a line X-X in FIG. 2 .

Each of the optical fibers 1 is formed of an optical fiber part 2, asheath layer 3, and a colored layer 4. The optical fiber part 2 isformed of a core and a clad. A diameter (clad diameter) of the opticalfiber part 2 is, for example, about 125 μm. The sheath layer 3 is alayer for coating the optical fiber part 2. The sheath layer 3 is formedof, for example, a primary sheath layer (primary coating) and asecondary sheath layer (secondary coating). The colored layer 4 is alayer formed on a surface of the sheath layer 3. The colored layer 4 isformed by applying a coloring material to the surface of the sheathlayer 3. A marking may be formed between the sheath layer 3 and thecolored layer 4. A first adhesive layer 5 is formed on a surface of thecolored layer 4. The first adhesive layer 5 is a layer formed byapplying, to the surface of the colored layer 4, a connection agent(ultraviolet curing resin) that forms the in-layer connection part 12,and curing the connection agent. Note that, when the plurality ofoptical fibers 1 constituting the intermittently connected optical fiberribbon 11 are separated into single fibers, the in-layer connection part12 is broken, and the first adhesive layer 5 is also peeled from thecolored layer 4.

FIG. 4B is a cross-sectional view of two optical fibers 1 connected bythe interlayer connection part 22.

Each of the optical fibers 1 is formed of the optical fiber part 2, thesheath layer 3, and the colored layer 4. The first adhesive layer 5 isformed on the surface of the colored layer 4. A second adhesive layer(interlayer connection part 22) is formed on a surface of the firstadhesive layer 5 between the two optical fibers 1. The second adhesivelayer (interlayer connection part 22) is a layer formed by applying, tothe surface of the first adhesive layer 5, a connection agent(ultraviolet curing resin) that forms the interlayer connection part 22,and curing the connection agent. Note that, when the plurality ofoptical fiber ribbons 11 constituting the optical fiber unit 10 areseparated, the interlayer connection part 22 is broken.

In one or more embodiments, as illustrated in FIG. 4B, the interlayerconnection part 22 is formed to a peripheral side than the in-layerconnection part 12. In other words, the interlayer connection part 22 isformed on the first adhesive layer 5 constituting the in-layerconnection part 12. In this way, it is easy to break the interlayerconnection part 22 while the in-layer connection part 12 remains. As aresult, when the intermittently connected optical fiber ribbon 11 istaken out from the optical fiber unit 10, the in-layer connection part12 is maintained even with the interlayer connection part 22 beingbroken, and thus a shape of the intermittently connected optical fiberribbon 11 can be maintained.

In the following description, as illustrated in FIG. 2 , it is assumedthat an interval between the in-layer connection parts 12 aligned in thelength direction (or a distance between centers of the in-layerconnection parts 12 in the length direction) is P1, and a length of thein-layer connection part 12 is A1. As illustrated in FIG. 1A, it isassumed that an interval between the interlayer connection parts 22aligned in the length direction (or a distance between centers of theinterlayer connection parts 22 in the length direction) is P2, and alength of the interlayer connection part 22 is A2.

FIG. 5A is an explanatory diagram of the optical fiber unit 10 accordingto one or more embodiments when viewed from the width direction. FIG. 5Bis an explanatory diagram of a situation where the interlayer separationpart 23 of the first tape 11A and the second tape 11B is opened up.

In one or more embodiments, the interval P2 between the interlayerconnection parts 22 is longer than the interval P1 between the in-layerconnection parts 12. In this way, as illustrated in FIG. 5B, theinterlayer separation part 23 of the first tape 11A and the second tape11B can be opened up by applying force in the length direction to theoptical fiber unit 10 so as to reduce the interval P2 between theinterlayer connection parts 22.

When the optical fiber ribbon 11 is taken out from the optical fiberunit 10, a finger or a division tool is inserted into the interlayerseparation part 23, and the inserted finger or the inserted divisiontool is made to slide in the length direction, and thus the interlayerconnection part 22 is broken (cut). In this way, when the optical fiberribbon 11 is taken out from the optical fiber unit 10, the interlayerseparation part 23 of the first tape 11A and the second tape 11B of theoptical fiber unit 10 can be widened as illustrated in FIG. 5B, whichmakes it easy to insert a finger or a division tool into the interlayerseparation part 23, and is thus convenient. Thus, it is preferable thatthe interval P2 between the interlayer connection parts 22 is longerthan the interval P1 between the in-layer connection parts 12. In otherwords, it is preferable that P2>P1.

In one or more embodiments, the length A2 of the interlayer connectionpart 22 is shorter than the length A1 of the in-layer connection part12. In this way, it is easier to break the interlayer connection part 22than the in-layer connection part 12. As a result, when theintermittently connected optical fiber ribbon 11 is taken out from theoptical fiber unit 10, it is easy to break the interlayer connectionpart 22 while the in-layer connection part 12 is maintained, and thus itis easy to maintain a shape of the intermittently connected opticalfiber ribbon 11.

In one or more embodiments, as illustrated in FIG. 1B, the interlayerconnection part 22 is not formed in a section in which the in-layerconnection part 12 of the optical fiber 1 at the end part is formed. Inother words, in one or more embodiments, the in-layer connection part 12is not formed in a section in which the interlayer connection part 22 ofthe optical fiber 1 in the end part is formed. In other words, in one ormore embodiments, the interlayer connection part 22 and the in-layerconnection part 12 are not formed in the same section of the opticalfiber 1. Note that, if the interlayer connection part 22 and thein-layer connection part 12 are formed in the same section of theoptical fiber 1, there is a possibility that the optical fiber 1 mayreceive lateral pressure in the section in a concentrated manner, and atransmission loss may increase. In contrast, in one or more embodiments,the interlayer connection part 22 and the in-layer connection part 12are not formed in the same section of the optical fiber 1, and thuslateral pressure applied to a specific section of the optical fiber 1 ina concentrated manner can be suppressed, and a transmission loss can besuppressed.

Method for Manufacturing Optical Fiber Unit 10

FIG. 6 is an explanatory diagram of a manufacturing system 30 formanufacturing the optical fiber unit 10. Here, for simplification of thedrawings, a method for manufacturing an eight-fiber optical fiber unit10 formed of two four-fiber intermittently connected optical fiberribbons 11 will be described.

The manufacturing system 30 includes two tape supply units 31, aunitization device 32, and a drum 33.

The tape supply unit 31 is a device (supply source) that supplies theintermittently connected optical fiber ribbon 11. Here, the tape supplyunit 31 includes a fiber supply unit 41, a printing device 42, acoloring device 43, and a taping device 44.

The fiber supply unit 41 is a device (supply source) that supplies theoptical fiber 1. Here, the fiber supply unit 41 supplies the single-coreoptical fiber 1 (the optical fiber 1 formed of the optical fiber part 2and the sheath layer 3; the optical fiber 1 before the colored layer 4is formed). However, the fiber supply unit 41 may supply a pair (thefiber pair 7: refer to FIG. 3 ) of two-line optical fibers 1. The fibersupply unit 41 supplies the optical fiber 1 to the printing device 42.

The printing device 42 is a device that prints a mark on the opticalfiber 1. For example, the printing device 42 prints a mark indicating atape number on each optical fiber 1. The plurality of optical fibers 1subjected to marking by the printing device 42 are supplied to thecoloring device 43.

The coloring device 43 is a device that forms the colored layer 4 of theoptical fiber 1. The coloring device 43 forms the colored layer 4 ofeach optical fiber 1 by an identification color for identifying theoptical fiber 1. Note that the identification color is a colorindicating an identification number (fiber number) of the optical fiber1. The coloring device 43 includes a coloring unit (not illustrated) foreach optical fiber 1, and each coloring unit applies a coloring agent(ultraviolet curing resin) of a predetermined identification color tothe surface of the optical fiber 1 (surface of the sheath layer 3). Thecoloring device 43 includes an ultraviolet irradiation unit (notillustrated), and the ultraviolet irradiation unit forms the coloredlayer 4 by irradiating, with ultraviolet rays, the coloring agent(ultraviolet curing resin) applied to the optical fiber 1, and curingthe coloring agent. The optical fiber 1 colored by the coloring device43 is supplied to the taping device 44. Note that the colored opticalfiber 1 may be supplied from the fiber supply unit 41 to the tapingdevice 44.

The taping device 44 is a device that intermittently forms the in-layerconnection part 12, and manufactures the intermittently connectedoptical fiber ribbon 11. The plurality of optical fibers 1 aligned inthe width direction are supplied to the taping device 44.

FIGS. 7A and 7B are explanatory diagrams of the taping device 44. Thetaping device 44 includes an application unit 441, a removal unit 442,and a light source 443.

The application unit 441 is a device that applies a connection agent(ultraviolet curing resin) that forms the in-layer connection part 12.The application unit 441 inserts the plurality of optical fibers 1 intoa coating die filled with a liquid connection agent, and thus applies,in the length direction, the liquid connection agent to a periphery ofthe optical fiber 1 and between the optical fibers 1 adjacent to eachother.

The removal unit 442 is a device that removes a part of the connectionagent applied by the application unit 441 while leaving a part of theconnection agent. The removal unit 442 includes a rotary blade 442Aincluding a recessed part 442B (refer to FIG. 7A). The rotary blade 442Ais arranged between two optical fibers 1, and rotates in accordance witha supply speed of the optical fibers 1. The connection agent applied bythe application unit 441 is intercepted by an outer edge of the rotaryblade 442A and removed, but the connection agent remains in the recessedpart 442B of the rotary blade 442A. The remaining section of theconnection agent becomes the in-layer connection part 12, and theremoved section of the connection agent becomes the non-connected part13.

The light source 443 is a device that irradiates, with ultraviolet rays,the connection agent formed of the ultraviolet curing resin. The lightsource 443 includes a temporary curing light source 443A and an actualcuring light source 443B. The temporary curing light source 443A isarranged upstream of the actual curing light source 443B. The connectionagent is temporarily cured by irradiation with ultraviolet rays from thetemporary curing light source 443A. The temporarily cured connectionagent is not completely cured, but curing proceeds on the surface. Theactual curing light source 443B actually cures the connection agent byirradiation with ultraviolet rays stronger than those of the temporarycuring light source 443A. The actually cured ultraviolet curing resin iscured to the inside (however, the in-layer connection part 12 afteractual curing has moderate elasticity).

As illustrated in FIG. 7B, the optical fibers 1 immediately afterleaving the application unit 441 and the removal unit 442 have aninterval therebetween. In this state, the temporary curing light source443A temporarily cures the connection agent by irradiating theconnection agent with ultraviolet rays. The taping device 44 graduallynarrows an interval between the optical fibers 1 after temporary curingof the connection agent, and arranges the plurality of optical fibers 1side by side and gathers them into a tape shape. Note that, since theconnection agent is temporarily cured, even if the removed parts(non-connected parts 13) of the connection agent contact each other, theremoved parts are not connected to each other. Since it is before actualcuring, an interval between the optical fibers 1 can also be narrowed(gathered) in a region in which the optical fibers 1 are connected bythe connection agent. When the connection agent is actually cured byirradiation with ultraviolet rays by the actual curing light source443B, the intermittently connected optical fiber ribbon 11 illustratedin FIG. 2 is manufactured.

The tape supply unit 31 (taping device 44) supplies the manufacturedintermittently connected optical fiber ribbon 11 to the unitizationdevice 32. Note that the tape supply unit 31 may supply, to theunitization device 32, the intermittently connected optical fiber ribbon11 from a drum around which the intermittently connected optical fiberribbon 11 is wound.

The unitization device 32 is a device that intermittently forms theinterlayer connection part 22, and manufactures the optical fiber unit10. The two intermittently connected optical fiber ribbons 11overlapping each other are supplied to the unitization device 32.

FIG. 8A is an explanatory diagram of the unitization device 32. Theunitization device 32 includes an application unit 321 and a lightsource 322.

The application unit 321 is a device that applies a connection agent(ultraviolet curing resin) that forms the interlayer connection part 22.The application unit 321 applies the connection agent that forms theinterlayer connection part 22 between two optical fibers 1 adjacent toeach other in the up-down direction in the end part in the widthdirection. Here, the application unit 321 is formed of a head thatdischarges the connection agent. In other words, the application unit321 applies the connection agent by an ink-jet printing method. The headincludes a nozzle row (not illustrated) in which a plurality of nozzles(not illustrated) are aligned in the up-down direction. A dischargesurface (a surface in which the nozzle row is formed) of the head isarranged so as to face the two optical fibers 1 adjacent to each otherin the up-down direction in the end part in the width direction. Theconnection agent is applied between the two optical fibers 1 bydischarging the connection agent from the nozzles.

FIG. 8B is an explanatory diagram of another application unit 321. Theapplication unit 321 is formed of a printing roller. In other words, theapplication unit 321 applies the connection agent by a roll printingmethod. Note that the application unit 321 includes, in addition to theprinting roller, a liquid tank (not illustrated) that houses theconnection agent, a supply roller (not illustrated) that scrapes up theconnection agent from the liquid tank and supplies the connection agentto the printing roller, a doctor blade (not illustrated), and the like.A streak part is formed on a surface of the printing roller by a meshpattern. The ultraviolet curing resin adheres to the streak part on thesurface of the printing roller (the ultraviolet curing resin fills in arecessed part (cell) in a printing plate), and the ultraviolet curingresin adhering to the streak part is transferred between the two opticalfibers 1 adjacent to each other in the up-down direction in the end partin the width direction.

The light source 322 is a device that irradiates, with ultraviolet rays,the connection agent formed of the ultraviolet curing resin. The lightsource 322 forms the interlayer connection part 22 by irradiating theconnection agent applied by the application unit 321 with ultravioletrays, and curing the connection agent.

The unitization device 32 forms the interlayer connection part 22, andthus the optical fiber unit 10 according to one or more embodiments ismanufactured. The optical fiber unit 10 manufactured by the unitizationdevice 32 is supplied to the drum 33.

The drum 33 is a member for winding the optical fiber unit 10. In one ormore embodiments, the non-connected part 13 is formed on theintermittently connected optical fiber ribbon 11, and the interlayerseparation part 23 is also formed between the two optical fiber ribbons11 of the optical fiber unit 10. Accordingly, the optical fibers 1 arenot firmly restrained and a movement of the optical fiber 1 in a crosssection is allowed, and thus the optical fiber unit 10 is easily woundaround the drum 33.

Machining Method for Optical Fiber Unit 10

FIG. 9 is a flowchart of an example of a machining method for theoptical fiber unit 10.

First, an operator breaks the interlayer connection part 22 in the endpart of the optical fiber unit 10, and separates the optical fiberribbon 11 (S101). For example, as illustrated in FIG. 5B, the operatorapplies force in the length direction to the optical fiber unit 10 so asto reduce the interval P2 between the interlayer connection parts 22,and opens up the interlayer separation part 23 of the first tape 11A andthe second tape 11B. Then, the operator inserts a finger or a divisiontool into the widened interlayer separation part 23, slides the insertedfinger or the inserted division tool in the length direction, and thusbreaks (cuts) the interlayer connection part 22. In this way, the firsttape 11A and the second tape 11B are separated.

Next, the operator separates the optical fibers 1 into single fibers inthe end part of the optical fiber unit 10 (S102). In other words, theoperator separates, into single fibers, the optical fibers 1 of thefirst tape 11A separated in S101, and also separates the optical fibers1 of the second tape 11B into single fibers. Note that the work issimilar to work for separating the optical fibers 1 of the normalintermittently connected optical fiber ribbon 11 into single fibers.

Next, the operator sets the optical fiber unit 10 in a holder 50 (S103).FIGS. 10A and 10B are explanatory diagrams of a situation where theoptical fiber unit 10 is set in the holder 50. A state of the opticalfibers 1 on a placement surface 51A of the holder 50 is illustrated onthe right side of each of the diagrams.

As illustrated in FIGS. 10A and 10B, the holder 50 includes a base part51 and a lid part 52. The base part 51 is a member for placing theoptical fibers 1. Note that the base part 51 may include a guide holeinto which a guide pin of a fusion splicing machine (not illustrated) isinserted. The lid part 52 is a member that can be open and closed withrespect to the base part 51. The lid part 52 is open and closed withrespect to the base part 51 with, as a shaft, a hinge part formedbetween the base part 51 and the lid part 52. The base part 51 includesa magnet 51B, and the lid part 52 is fixed by the magnet 51B when thelid part 52 is closed. The lid part 52 includes a press part 52A, andthe plurality of optical fibers 1 of the optical fiber unit 10 aresandwiched between the placement surface 51A of the base part 51 and thepress part 52A when the lid part 52 is closed.

In one or more embodiments, as illustrated in FIG. 10B, when theplurality of optical fibers 1 of the optical fiber unit 10 aresandwiched between the placement surface 51A of the base part 51 and thepress part 52A of the lid part 52 with the lid part 52 closed, theoptical fiber 1 of the first tape 11A enters between the optical fibers1 of the second tape 11B (or the optical fiber 1 of the second tape 11Benters between the optical fibers 1 of the first tape 11A), and theplurality of layered and arranged optical fibers 1 of the optical fiberunit 10 are arranged in one row on the placement surface 51A. In thisway, it is possible to machine the plurality of layered and arrangedoptical fibers 1 of the optical fiber unit 10 by using a normal tool(for example, a sheath removing device and a cutting device: refer toS104 and S105 described later).

Note that, since the plurality of optical fibers 1 of the optical fiberunit 10 are arranged in one row on the placement surface 51A in such amanner, it is preferable that the optical fibers 1 sandwiched betweenthe placement surface 51A and the press part 52A are separated intosingle fibers. In other words, it is preferable that the interlayerconnection part 22 is broken in a section sandwiched between theplacement surface 51A and the press part 52A in S101 described above,and the in-layer connection part 12 is broken in the section sandwichedbetween the placement surface 51A and the press part 52A in S102. Notethat, if the interlayer connection part 22 and the in-layer connectionpart 12 remain in the section sandwiched between the placement surface51A and the press part 52A, it is difficult for the optical fiber 1 ofthe first tape 11A to enter between the optical fibers 1 of the secondtape 11B, and thus it is difficult to arrange the plurality of layeredand arranged optical fibers 1 of the optical fiber unit 10 in one row onthe placement surface 51A. In contrast, in one or more embodiments, theinterlayer connection part 22 and the in-layer connection part 12 in thesection sandwiched between the placement surface 51A and the press part52A are broken, and all the optical fibers 1 in the section sandwichedbetween the placement surface 51A and the press part 52A are separatedinto single fibers. Thus, when the plurality of optical fibers 1 of theoptical fiber unit 10 are sandwiched between the placement surface 51Aof the base part 51 and the press part 52A of the lid part 52, theplurality of layered and arranged optical fibers 1 of the optical fiberunit 10 can be arranged in one row on the placement surface 51A.

Next, the operator removes sheaths of the optical fibers 1 of theoptical fiber unit 10 (S104). FIGS. 11A to 11C are explanatory diagramsof a situation where sheaths of the optical fibers 1 of the opticalfiber unit 10 are removed.

As illustrated in FIG. 11A, the operator sets the holder 50 that holdsthe optical fiber unit 10 in a holder stand of a holding part 62 of asheath removing device 60 (hot jacket stripper). As already described,the optical fiber unit 10 with the plurality of optical fibers 1arranged in one row is set in the holder 50. Thus, when the operatorsets the holder 50 in the holder stand, the plurality of optical fibers1 extending from the holder 50 are aligned and placed in one row in thewidth direction on a heating surface 61A of a body part 61 of the sheathremoving device 60. Thus, both of the optical fibers 1 of the first tape11A and the optical fibers 1 of the second tape 11B can be heated by thesame heating surface 61A.

Next, as illustrated in FIG. 11B, the operator closes a lid of the bodypart 61 and a lid of the holding part 62. When the lid of the body part61 is closed, the plurality of optical fibers 1 (the optical fibers 1 ofthe first tape 11A and the second tape 11B arranged in one row)extending from the holder 50 are sandwiched between a pair of blades 61B(refer to FIG. 11C), and a cut is put in sheaths of the optical fibers 1by the pair of blades 61B. In one or more embodiments, since the opticalfibers 1 of the optical fiber unit 10 are aligned in one row in thewidth direction, a cut is put in both of sheaths of the optical fibers 1of the first tape 11A and sheaths of the optical fibers 1 of the secondtape 11B by the pair of blades 61B. Note that, when the lid of the bodypart 61 is closed, sheaths in the end part of the optical fibers 1 areheated by the heating surface 61A. When the sheaths in the end part ofthe optical fibers 1 are heated, the sheaths become soft and become easyto remove.

Next, as illustrated in FIG. 11C, the operator moves the holding part 62rearward with respect to the body part 61 with the lid closed, andseparates the body part 61 and the holding part 62. In this way, thesheaths in the end part of the optical fibers 1 are pulled by the pairof blades 61B, and the sheaths of the optical fibers 1 are removed. Inone or more embodiments, since the optical fibers 1 of the optical fiberunit 10 are aligned in one row in the width direction, both of thesheaths of the optical fibers 1 of the first tape 11A and the sheaths ofthe optical fibers 1 of the second tape 11B can be removed together bythe pair of blades 61B. In one or more embodiments, since the sheaths ofthe optical fibers 1 of the first tape 11A and the second tape 11B areremoved by the same blades 61B, peeling edges of the sheaths can belined up.

Next, the operator cuts the optical fibers 1 of the optical fiber unit10. The operator sets the holder 50 that holds the optical fiber unit 10in a cutting device (not illustrated). As already described, the opticalfiber unit 10 with the plurality of optical fibers 1 arranged in one rowis set in the holder 50. The optical fibers 1 having the sheaths removedin S104 extend from the holder 50. Then, the operator puts an initialscratch in the optical fibers 1 (optical fibers 1 having the sheathsremoved) aligned in one row in the width direction by moving a cuttingblade in the width direction, and also cuts the optical fibers 1 byrupturing (cleaving) the optical fibers 1 from the initial scratch. Inthis way, both of the optical fibers 1 of the first tape 11A and theoptical fibers 1 of the second tape 11B of the optical fiber unit 10 canbe cut together. Since the optical fibers 1 are cut by the same cuttingblade, endfaces of the optical fibers 1 can line up.

The prior processing of the optical fibers 1 is completed by themachining processing in S101 to S105 described above. The plurality ofoptical fibers 1 of the optical fiber unit 10 according to one or moreembodiments are layered and arranged, but sheaths can be removed in thesame position and the optical fibers 1 can be cut in the same positionby setting the optical fiber unit 10 in the holder 50 and arranging theoptical fibers 1 in one row.

After the prior processing, the operator performs post processing. Asthe post processing, a ferrule may be attached, and fusion splicing ofthe optical fibers 1 may be performed. For example, when a ferrule inwhich fiber holes are formed in many stages is attached, the pluralityof optical fibers 1 of the optical fiber unit 10 according to one ormore embodiments can be inserted together into each of the fiber holesof the ferrule. When the optical fibers 1 are fusion-spliced, the holder50 that holds the optical fiber unit 10 is set in a fusion splicingmachine (not illustrated), and the plurality of optical fibers 1 of theoptical fiber unit 10 can be fusion-spliced together. In this case, whenthe optical fiber unit 10 is set in the holder 50, the optical fibers 1of the first tape 11A and the optical fibers 1 of the second tape 11Bneed to be arranged in one row in a predetermined order. Thus, when theoptical fiber unit 10 is set in the holder 50, it is preferable that theoptical fibers 1 of the first tape 11A and the optical fibers 1 of thesecond tape 11B are alternately arranged in one row.

Modification Example

FIG. 12A is an explanatory diagram of the optical fiber unit 10according to a modification example of one or more embodiments. FIG. 12Bis a cross-sectional view in a position including the interlayerconnection part 22. FIG. 12C is a cross-sectional view in a positionthat does not include the interlayer connection part 22. As illustratedin FIG. 12A, a mark 8 indicating a first tape is formed on the firsttape 11A. Note that, although not illustrated in FIG. 12A, a mark 8indicating a second tape is formed on the second tape 11B on a lowerside.

In the optical fiber unit 10 according to the modification example, theoptical fibers 1 having the same fiber number of the first tape 11A andthe second tape 11B are aligned in the up-down direction in a slightlyshifted state in the width direction (specifically, in a shifted stateby about half of a fiber interval in the width direction). In this way,the optical fibers 1 having the same fiber number being aligned in theup-down direction may not be located in the same position in the widthdirection, and may be slightly shifted in the width direction. However,in one or more embodiments, the optical fibers 1 having the same fibernumber of the first tape 11A and the second tape 11B are aligned in theup-down direction, and thus a shift amount in the width direction of theoptical fibers 1 having the same fiber number is less than a fiberinterval.

FIG. 13 is an explanatory diagram of a situation where the optical fiberunit 10 according to the modification example illustrated in FIG. 12A isset in the holder 50. As already described, when the optical fiber unit10 is sandwiched between the placement surface 51A of the base part 51and the press part 52A of the lid part 52, the plurality of layered andarranged optical fibers 1 of the optical fiber unit 10 are arranged inone row on the placement surface 51A.

In the optical fiber unit 10 according to the modification example, theoptical fibers 1 having the same fiber number are aligned in the up-downdirection while being slightly shifted in the width direction, and thusthe optical fibers 1 of the first tape 11A and the optical fibers 1 ofthe second tape 11B are alternately aligned in one row when the opticalfiber unit 10 is sandwiched between the placement surface 51A of thebase part 51 and the press part 52A of the lid part 52. In other words,according to the modification example, when the optical fiber unit 10 isset in the holder 50, the optical fibers 1 of the first tape 11A and theoptical fibers 1 of the second tape 11B can be arranged in one row in apredetermined order.

Whether the plurality of optical fibers set in the holder 50 arearranged in a predetermined order is difficult to determine only by anidentification color of the optical fibers 1. Thus, according to themodification example, it is preferable that the mark 8 indicating a tapenumber is formed on each optical fiber ribbon of the optical fiber unit10. In this way, as illustrated in FIG. 13 , whether the optical fibers1 of the first tape 11A and the optical fibers 1 of the second tape 11Bare alternately aligned can be determined based on the mark 8 of theoptical fibers 1 set in the holder 50 and aligned in one row. Note thatdetermination based on the mark 8 of the optical fibers 1 aligned in onerow may be performed by visual confirmation by an operator. However, amachining machine (such as a sheath removing device, a cutting device,and a fusion splicing machine) may include a function of identifying themark 8, and the machining machine may determine whether the opticalfibers 1 of the first tape 11A and the optical fibers 1 of the secondtape 11B are alternately aligned, based on the mark 8 of the opticalfibers 1 aligned in one row.

FIGS. 14A and 14B are explanatory diagrams of an optical fiber unit 10according to one or more embodiments.

The optical fiber unit 10 according to one or more embodiments includesthree intermittently connected optical fiber ribbons 11 (a first tape11A, a second tape 11B, and a third tape 11C). Also in one or moreembodiments, the three intermittently connected optical fiber ribbons 11are aligned and layered in the up-down direction such that opticalfibers 1 having the same fiber number are aligned in the up-downdirection. In the optical fiber unit 10 according to one or moreembodiments, the first tape 11A and the second tape 11B areintermittently connected by an interlayer connection part 22 in thelength direction, and the second tape 11B and the third tape 11C arealso intermittently connected by the interlayer connection part 22 inthe length direction. In this way, the intermittently connected opticalfiber ribbon 11 constituting the optical fiber unit 10 is not limited totwo, and may be three or more.

As illustrated in FIG. 14B, the interlayer connection part 22 thatconnects the first tape 11A and the second tape 11B and the interlayerconnection part 22 that connects the second tape 11B and the third tape11C are formed in the same position in the length direction. In thisway, since the two interlayer connection parts 22 are aligned in theup-down direction, the two interlayer connection parts 22 can be formedby a simple method. For example, when the two interlayer connectionparts 22 are aligned in the up-down direction and formed, the rollprinting method (refer to FIG. 8B) described above can be adopted.

FIGS. 15A and 15B are explanatory diagrams of the optical fiber unit 10according to a modification example of one or more embodiments.

In the modification example, the interlayer connection part 22 thatconnects the first tape 11A and the second tape 11B and the interlayerconnection part 22 that connects the second tape 11B and the third tape11C are formed in different positions in the length direction. In thisway, it is possible to perform an arrangement such that a position inthe length direction of an interlayer separation part 23 of the firsttape 11A and the second tape 11B is shifted with respect to a positionin the length direction of the interlayer separation part 23 of thesecond tape 11B and the third tape 11C. As a result, in the modificationexample, as illustrated in FIG. 15B, when force in the length directionis applied to the optical fiber unit 10 so as to reduce an intervalbetween the interlayer connection parts 22, a position in which theinterlayer separation part 23 of the first tape 11A and the second tape11B is opened up is shifted with respect to a position in which theinterlayer separation part 23 of the first tape 11A and the second tape11B is opened up, and thus work for taking out a desired optical fiberribbon 11 from the optical fiber unit 10 is facilitated.

Note that, when the interlayer connection part 22 is formed as in themodification example, it is preferable to adopt the ink-jet printingmethod (refer to FIG. 8A) described above.

Although the disclosure has been described with respect to only alimited number of embodiments, those skilled in the art, having benefitof this disclosure, will appreciate that various other embodiments maybe devised without departing from the scope of the present invention.Accordingly, the scope of the invention should be limited only by theattached claims.

REFERENCE SIGNS LIST

-   1: Optical fiber;-   1A: First fiber;-   1N: Twelfth fiber;-   2: Optical fiber part;-   3: Sheath layer;-   4: Colored layer;-   5: First adhesive layer;-   7: Fiber pair;-   8: Mark;-   10: Optical fiber unit;-   11: Optical fiber ribbon;-   11A: First tape;-   11B: Second tape;-   12: In-layer connection part;-   13: Non-connected part;-   22: Interlayer connection part;-   23: Interlayer separation part;-   30: Manufacturing system;-   31: Tape supply unit;-   32: Unitization device;-   321: Application unit;-   322: Light source;-   33: Drum;-   41: Fiber supply unit;-   42: Printing device;-   43: Coloring device;-   44: Taping device;-   441: Application unit;-   442: Removal unit;-   442A: Rotary blade;-   442B: Recessed part;-   443: Light source;-   443A: Temporary curing light source;-   443B: Actual curing light source;-   50: Holder;-   51: Base part;-   51A: Placement surface;-   51B: Magnet;-   52: Lid part;-   52A: Press part;-   60: Sheath removing device;-   61: Body part;-   61A: Heating surface;-   61B: Blade;-   62: Holding part.

1. A machining method for an optical fiber unit, the machining methodcomprising: preparing an optical fiber unit in which a first opticalfiber ribbon that intermittently connects a first plurality of opticalfibers and a second optical fiber ribbon that intermittently connects asecond plurality of optical fibers are layered and arranged, the firstoptical fiber ribbon and the second optical fiber ribbon areintermittently connected in a length direction by interlayer connectionparts; opening up a separation part between the first optical fiberribbon and the second optical fiber ribbon; and breaking the interlayerconnection parts by inserting a finger or a division tool into theopened separation part.
 2. A machining method for an optical fiber unit,the machining method comprising: preparing an optical fiber unit inwhich a first optical fiber ribbon that intermittently connects a firstplurality of optical fibers and a second optical fiber ribbon thatintermittently connects a second plurality of optical fibers are layeredand arranged, the first optical fiber ribbon and the second opticalfiber ribbon are intermittently connected in a length direction byinterlayer connection parts; separating the first plurality of opticalfibers of the first optical fiber ribbon and the second plurality ofoptical fibers of the second optical fiber ribbon into a plurality ofsingle optical fibers in an end part of the optical fiber unit in thelength direction; and arranging the plurality of single optical fibersin one row by setting the optical fiber unit in a holder.
 3. Themachining method for an optical fiber unit according to claim 2, furthercomprising: setting, in a sheath removing device, the holder in whichthe plurality of single optical fibers of the optical fiber unit arearranged in one row; and removing sheaths of the first plurality ofoptical fibers of the first optical fiber ribbon and sheaths of thesecond plurality of optical fibers of the second optical fiber ribbontogether using a pair of blades of the sheath removing device.
 4. Themachining method for an optical fiber unit according to claim 2, furthercomprising: setting, in a cutting device, the holder in which theplurality of single optical fibers of the optical fiber unit arearranged in one row; and cutting the first plurality of optical fibersof the first optical fiber ribbon and the second plurality of opticalfibers of the second optical fiber ribbon together by moving a cuttingblade of the cutting device in a direction in which the plurality ofoptical fibers are aligned.
 5. The machining method for an optical fiberunit according to claim 1, wherein when opening up the separation part,a force is applied in the length direction to the optical fiber unit toreduce an interval between the interlayer connection parts.
 6. Themachining method for an optical fiber unit according to claim 2, whereinthe holder includes a base part and a lid part, and when arranging theplurality of the optical fibers in one row, the plurality of layered andarranged single optical fibers of the optical fiber unit are sandwichedbetween the base part and the lid part.